Which of the following statements will execute only if the conditions A and B are true?

The correct choice here pertains to the logical structure used in programming for executing statements based on the evaluation of certain conditions.

In the context of Javascript, the most straightforward mechanism to execute a block of code only when specific conditions are true is through an If statement. An If statement checks a condition and executes the block of code within it only if that condition evaluates to true. You can also use logical operators to combine multiple conditions, such as "A && B", which signifies that both A and B must be true for the block to execute.

Choices like Run-Time, While Loop, and For Loop don't specifically execute based on the simultaneous truth of conditions A and B in the same straightforward manner. While loops and For loops execute a block of code repeatedly, which can include condition checks, they are not explicitly designed to run only based on the truth of two conditions from the outset.

The Run-Time choice does not pertain to a specific control structure for executing code based on conditions, making it irrelevant as well. Thus, the If statement is the correct mechanism for achieving the required functionality of conditional execution based solely on A and B being true.